1. Field of the Invention
This invention relates generally to continuous flow grain drying apparatus.
2. Description of the Prior Art
In the storage of grain such as corn, it is a common practice to dry the grain to remove a portion of the moisture content thereof. Many types of batch-type and continuous flow grain drying apparatus have been proposed and used. Typically, such prior grain drying apparatus included one or more chambers arranged to permit a flow of grain to gravitate downwardly therethrough, the grain being first subjected to a flow of heated, dry air which removes moisture and thereafter is subjected to a flow of cool air so as to cool the grain.
In one type of prior grain drying apparatus, the grain is passed through the apparatus in a single, relatively large column thus requiring the use of a multiplicity of air inlet and outlet ducts in order to minimize the length of the air flow paths through the grain. Further, passing the grain through the drying apparatus in a single column results in some portion of the grain being subjected to more or less heating and cooling than other portions.
U.S. Pat. No. 3,526,969 to Erhard E. Alms and James E. Mitchell discloses batch-type grain drying apparatus having separate drying and cooling chambers. Batch-type grain drying apparatus of the type shown in the aforesaid Alms et al patent employing only a drying chamber has also been used.
British Pat. No. 326,871 discloses continuous flow grain drying apparatus employing counter-flow of drying air.
In certain installations, by reason of its increased capacity, greater heating and cooling efficiency, and reduced operating expense continuous flow grain drying apparatus is preferred to the batch-type apparatus. Since there are many existent installations of batch-type drying apparatus of the type shown in the aforesaid Alms et al patent, it is desirable to convert such batch-type apparatus to continuous flow apparatus.
My U.S. Pat. No. 3,869,809, granted Mar. 11, 1975 (allowed application Ser. No. 397,068, filed Sept. 13, 1973) discloses continuous flow grain drying apparatus employing the drying chamber portion of batch-type drying apparatus, such as that shown in the aforesaid Alms et al patent, but eliminating the holding bin and cooling chambers, if any, and adding thereto a new cooling chamber with flow dividing means in the drying and cooling chambers providing a pair of passages therethrough thus dividing the downward flow of grain into two separate, parallel streams.